Method of treating molds used in the art of electrotyping.



I York,

outrun STATES PATENT 0FFIo GEORGE E. DUNTON, OF NEW YORK, N. Y.

METHOD or TREATING Moms USED IN THE ART or ELECTROTYPING.

1 ,002, 658. No Drawing.

To all whom it may concern.

- Be it known that-I, GEORGE "E. DUNTON, residln at New York city,county of New tate of New York, a citizen of the United States, haveinvented certain new and useful Improvements in Methods of TreatingMolds Used in the Art of Electrotyping; and I do hereby declare thefollowing to be a full, clear, and exact description of the invention,such as will enable others skilled in the art to which it pertains tomake and use the same.

My invention relates to a new and improved method of treating molds, andmore especially the wax molds used in the manufacture of electro-typeprinting plates in the art of electrotyping.

The material of which the molds are formed for the production ofprinting plates in-the electrotyping art is generally beeswax, ozokeritewax or like substance which contains an appreciable percentage ofgrease, oil or oily substance in its composition. In bees-wax, thegrease is due to the presence of palinitin and in ozokerite wax, mineralwax, it is due to the presence of petroleum.

When pressure is applied to a form or cut in making the impression inthe mold, it causes any grease or oily substance therein to be expressedor forced out and'appear on the face of the mold in the form of a thincoating or film, and said coating or film very troublesome and annoyingto the electrotyper as it causes imperfect and faulty reproductions.Especially in case where the so-called half tone illustrations are beingmade, which are composed or made up of a collection of very fine dots,or in the duplicating of color plates where three or four or even moreprintings are necessary, the least variation from the original plate,such as the filling up of the minute indentations made by each dot inthe wax mold, wouldresult in a thickening of the duplicate orreproduction and ruin the same.

More trouble has heretofore been experienced in the uncertainty ofreproducing faithfully duplicates of the original half tone plates andby all the common well known processes, the finer dots of electrotypeduplicates from half tones do not have their proper height or facesurface, thatis, instead of having a well defined flat, clear out orsharp printing surface the points are Specification of Letters Patent.Applicationnled November 11 1910', Serial No; 591,893.

Patented Sept. 5, 1911.

rounded and lacking in height from onefourth to one-half of theoriginal.

After a very carefulstudy and extensive experiments, I havedemonstrated. the fact that the above conditions are due to the in theblack lead from the Wax mold. The

deeper portions of the impressions in the mold, the points of the dotspenetrating further into the wax, receive and retain a ,largerproportion or percentage of this grease and when the black lead isapplied to the surface of the mold the retained grease in the dotsdistributes itself throughout among the particles of lead, with which itcomes in contact, and holds the particlesfirmly together and in contactwith the sharp edges of the bottom of the dot re.- cesses made in thewax. The use of a machine, either an air blast, wet method or brush typeserves to pack the black lead firmly into the dots in the wax mold, and

the grease serves as a binder to cementthe particles of the black leadtogether and hold the mass at the bottom of the dotrecess.

Experiments have shown me that no amount of brushin blowing or washing,by using a spray 0 water undervpressure, will loosen or remove thecongested particles of black lead from the wax mold, consequently whenthe deposit takes place instead of the metal going to the fullest depthof the dot recess it deposits over the accumulated film of black lead atthe bottom of the dot recess, producing as a result round headed dotswhich have lost .just that, value the accumulated black lead hasacquired at the bottom of the dot recess in the wax mold. The onlymanner whereby this surplus accumulation of black lead can be dlslodgedor removed is to dissolve'the grease, oil or oily substance, which ashas been said before is forced out ofthe mold, by treating it chemicallywhen it may be easily removed.

Experiments have demonstrated the fact that the grease, oil or oilysubstance expressed from the mold can be removed by mixing a greaseconverting substance, preferably a chemical substance, with the blacklead which is used to render the mold conductive, and that when thecombined black lead and grease converting substance is applied to themold it will convert the grease and also 'renderthe mold conductive,after which the converted substance can easily be rinsed or washed oilby water, chemical, mechanical or other suitable means;

By my method, before applying the black lead'to the mold, I mix a greaseconverting substance with the black lead and then-apply said combinedsubstance 'to the mold, and after the grease has been converted intoanother substance, for instance, a saponaceous substance, I remove saidconverted sa 0- naceous substance from the mold by washmg saidimold withwater, when the black lead and mold will be free from grease andready togo through the other necessary operations well knowniin the art, whichare not neces-.

sary'to enumerate, when the mold will be in condition for use.

By the above method, which removes all the grease, oil or oilysubstance, the dots and recesses of the mold are left clear, and un- 4obstructed and a duplicate or reproduction taken from the same it willbe a clear cut perfect plate. I

What I claim is 1. The method of treating molds used in the art ofelectrotyping, consisting in mixing a: grease converting substance witha conducting substance, designed to render the mold conductive, applyingthe resultant combined convertin and conductive substance to the mold tosimultaneously render it conductive and convert the grease expressedtherefrom and finally removing the converted substance, substantially asdescribed.

4 2. The method-of treating molds used in the art of electrotyping,consisting in mixmg a ease converting substance with a conductlvesubstance, designed to render the mold conductive, applying theresultant combined converting and conductive substance to the mold torender it conductive and convert the grease expressed therefrom andfinally removing the converted substance by chemical means,substantially as described.

3. The method of treating molds used in the art of electrotyping,consisting in sub jecting the mold to the action of a combined greaseconverting and electric conducting substance and then removing theconverte substance, substantially as described.

4. The method of treating molds used in the art of electrotyping,consisting in sub-- jecting the mold to the action of a combined greaseconverting and electric conductin substance and thenremoving'theconverte substance by chemical means, substantially as described.

i In testimony whereof, I afiix my signature in the presence of twowitnesses.

GEORGE E. DUNTON. i Witnesses:

H. BECKER, F. DUFF.

